'How I Met Your Mother' Hid A Brilliant Joke You Never Noticed

Wait for it ...

Think you know everything there is about "How I Met Your Mother"? To that, Barney would say, "Challenge accepted."

Not too long ago, the Internet became privy to the fact that there was a deeper meaning to Tracy and Ted's song, "La Vie en Rose," and now another realization just might blow your mind.

Imgur user Eclipezz points out that it all happens in Season 9, Episode 12, "The Rehearsal Dinner." In one sequence, the group is making fun of Robin for suggesting that she and Barney get married in Canada. After a few jokes, Robin says, "Two mitten jokes in a row, so you're pretty much done then?"

Ted's voiceover says, "Kids, we weren't even close." And to prove just how long they were making Canada wisecracks, the writers hid something legendary in the background. Wait for it ...